diff -r 7ca11ecbc4fb -r dcbef866c9e2 src/HOL/Orderings.thy
--- a/src/HOL/Orderings.thy	Mon Nov 17 17:00:27 2008 +0100
+++ b/src/HOL/Orderings.thy	Mon Nov 17 17:00:55 2008 +0100
@@ -71,7 +71,7 @@
 
 lemma dual_preorder:
   "preorder (op \<ge>) (op >)"
-by unfold_locales (auto simp add: less_le_not_le intro: order_trans)
+proof qed (auto simp add: less_le_not_le intro: order_trans)
 
 end